CALIBRATION OF DP LEVEL TRANSMITTER (ELEVATION) :

In this article, we will we discussing Calibration of the DP transmitter when the transmitter installed above 0% level.


(1) DRY LEG





Let, consider the above-stated example in which we have a height from the centre to centre tapping is 5470 mm and the height from 0% to HP connection is 1250 mm.


1. Calculate Range :


Range = centre to centre (0% to 100%) * S.G.

= 5470 * 1.12

Range = 6126.4 mmH20


2. Calculate LRV :


LRV = HP - LP

= (1.12 * (-1250)) - 0


(Here transmitter installed in elevation so we have minus the height and in suppression, we have to add that height.)


LRV = -1400 mmH20


3. Calculate URV :


URV = LRV + Range

= 6126.4 - 1400

URV = 4726.4 mmH2o


(2) WET LEG




Now let consider same example as above with this time for wet leg having a specific gravity of 1.17


1. Calculate Range :


Range = centre to centre (0% to 100%) * S.G.

= 5470 * 1.12

Range = 6126.4 mmH2o


2. Calculate LRV :


LRV = HP - LP

= (-1250 * 1.12) - (4490 * 1.17)

(Due to wet leg and elevation height is 5470 + 270 - 1250 = 4490)

= - 1400 - 5253.3

LRV = -6653.3 mmH2o


3. Calculate URV :


URV = LRV + Range

= -6653.3 + 6126.4

URV = -526.9 mmH2o


After calculation of LRV and URV put this value in the transmitter.

CALIBRATION

CONTROL VALVE

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